It’s the End of the World as We Know It and I Feel Fine.
An ode by R.E.M. seems to be spinning in my head.
With the polls for the Israeli elections indicating a victory for Ehud Olmert and Kadima, Muslim rage continuing in Iraq and elsewhere, Hamas and Abu Abbas of the Palestinian Authority continuing political talks, the news regarding Iran’s proclivity in assuring their people that they will be the next evil-axis state to attain nuclear power has been put on the backburner.
The funny thing is that the Iranian Islamists are Shiites who are not Arabs and they wish to be the leaders of both the Sunni and Shiite Pan-Arab nationalist movement.
To Arab Sunni Islamists, Iranians are Zoroastrians. Shiites, including Arab ones, on the other hand, are heretics who must be "re-converted" or put to death.
Of course, that shouldn’t be surprising, with the current trial, in “liberal” Afghanistan, of the Muslim who became a Christian convert facing a possible death sentence. You know, it’s that moral Sharia law.
Well, as Amir Teheri so eloquently put it, everything will be fine as soon as Iran “destroys” Israel. Then Iran’s mortal enemies, i.e. the rest of the Arab world, can focus on destroying Iran. Wow; nuclear proliferation, what a concept!
But why worry about these mundane matters.
In a recent issue of New Scientist, two articles suggest the world really looks like it’s coming to an end.
In the article entitled “grudge match,” the ‘hockey stick’ theory is presented where global warming is presented as a graph whereby the last thousand years appear as the shaft of a hockey stick, with no increase in global warming, while the last few years are the blade of the hockey stick which points up and indicates massive global warming beginning now.
In the second article entitled “Nightmare in Manhattan”, a nightmare scenario is presented whereby a small nuclear device is detonated in New York City.
Oh well, we can still hum R.E. M. songs: ‘First We Take Manhattan…’
See the articles below:
http://www.newscientist.com/channel/health/mg18925431.300.html
Nuclear nightmare in Manhattan
A truck pulls up in front of New York City's Grand Central Station, one of the most densely crowded spots in the world. It is a typical weekday afternoon, with over half a million people in the immediate area, working, shopping or just passing through. A few moments later the driver makes his delivery: a 10-kiloton atomic explosion.
Almost instantly, an electromagnetic pulse knocks out all electronics within a radius of 4 kilometres. The shock wave levels every building within a half-kilometre, killing everyone inside, and severely damages virtually all buildings for a kilometre in every direction. Detonation temperatures of millions of degrees ignite a firestorm that rapidly engulfs the area, generating winds of 600 kilometres an hour.
Within seconds, the blast, heat and direct exposure to radiation have killed several hundred thousand people. Perhaps they are the lucky ones. What follows is, if anything, even worse.
The explosion scoops out a crater 20 metres across and 10 metres deep, sending thousands of tonnes of highly radioactive debris into the air as a cloud of dust. What goes up must come down, and radioactive detritus starts piling up.
Within the first hour, enough fallout settles to fatally irradiate tens of thousands of people in the immediate area. Even 20 kilometres downwind, the majority of people caught in the path of the plume are exposed to life-threatening levels of radioactivity. Anyone less than 30 kilometres downwind will need to get out or find shelter, fast. For 150 kilometres or more downwind of the blast, dangerous amounts of fallout continue to drizzle down.
This nightmare scenario is one the US government is taking seriously. In the past two years alone, it has committed hundreds of millions of dollars to dealing with the aftermath of an act of urban nuclear terrorism, or a 9/11-style attack on a nuclear plant.
Making a bomb is not as difficult as you might imagine. The "gun-type" atomic weapon akin to the one dropped on Hiroshima is essentially a matter of shooting one piece of highly enriched uranium into another. Princeton University physicist Frank von Hippel, in a New York Times interview not long after 9/11, estimated that simply dropping a 45-kilogram lump of weapons-grade uranium onto a second piece of a similar size from a height of about 1.8 metres could produce a blast of 5 to 10 kilotons - that is, the explosive force of 5000 to 10,000 tons of TNT. With enough highly enriched uranium in the world to make hundreds of thousands of such weapons, and frequent reports of nuclear material being stolen from the former Soviet Union, it is far from unthinkable that terrorists could get their hands on enough to make a bomb.
In 2004, a US government-funded working group published an estimate of the number of radiation casualties that would follow a 10-kiloton detonation in a mid-sized city of 2 million, the size of Washington DC (Annals of Internal Medicine, vol 140, p 1037). The numbers make for sobering reading: 13,000 killed immediately; 45,000 facing certain death regardless of treatment; 255,000 at risk of dying without hospital treatment; and a further 140,000 in need of observation. Even a 1-kiloton explosion, from a smaller device or an imperfectly executed detonation, would produce perhaps a third to a half that number of radiation casualties, according to group member Jamie Waselenko of the Sarah Cannon Research Institute in Nashville, Tennessee.
It is the quarter of a million lives that could be saved that are exercising the minds of US policymakers. All of those casualties will be suffering from acute radiation syndrome, otherwise known as radiation sickness. All are potential survivors, but at present there would be little that doctors could do for them.
Most of what is known about radiation sickness comes from animal studies and accidents, and from medical records from Hiroshima and Nagasaki. The syndrome is a collection of symptoms that get progressively worse with increasing exposures. The simplest measure of exposure is a unit called a gray - the number of joules of radiation energy absorbed per kilogram of tissue.
Walking dead
Any exposure above 2 grays or so is deadly serious. People irradiated to this level or higher quickly get sick, then get better again. However, this "latent phase" is only temporary. Some time later, from a few days to a month, they fall ill again, and often die. Not surprisingly, the more radiation you absorb, the more organs are involved, the quicker the immediate symptoms come on and the shorter the latent phase.
The body's most susceptible vital tissue is the bone marrow, specifically the stem cells within it that give rise to new blood cells. These are impaired at doses as low as half a gray and are usually wiped out completely and permanently above 5 grays. When the stem cells die, blood-cell counts - most critically those of neutrophils and platelets - start to drop, eventually plunging to zero after days or weeks. Without neutrophils, the first-responders of the immune system, radiation victims are at high risk of opportunistic infections. Losing platelets is also seriously bad news: without them blood cannot clot, leading to potentially fatal bleeding from even the smallest wound.
Upwards of 5 grays, the gastrointestinal tract is also affected. Radiation kills any rapidly dividing cells, such as the ones lining the intestinal tract. The resulting damage can cause gut bacteria to leak into the bloodstream, where they overwhelm the already compromised immune system and cause septic shock. At exposures above 10 grays, the central nervous system is damaged too, and death is certain, with or without treatment.
The standard treatment for radiation syndrome is "supportive care": blood and platelet transfusions, antimicrobials, fluids, anti-emetics and other "comfort measures". These treatments are better than nothing but are often not enough, and would be extremely difficult to deliver on a mass scale in the aftermath of a nuclear attack. Which means that despite receiving technically survivable doses of radiation, a large proportion of those 255,000 people will die.
The US government is determined to shift the odds in their favour. "What we're aiming to do is to be able to treat every casualty," says Norm Coleman of the National Cancer Institute in Bethesda, Maryland, who has been helping the Department of Health and Human Services plan its response to a nuclear attack.
The government is putting its money where its mouth is. In 2005 it awarded a total of $47 million to several groups of radiation researchers, including $29 million to the newly formed Centers for Medical Countermeasures against Radiation (CMCR). Their mission is to gain a better understanding of the biology of radiation damage, find faster ways of diagnosing radiation exposure levels, and discover better drugs. In July 2004 President Bush signed the Bioshield Act into law, committing $5.6 billion to counter nuclear, biological and chemical threats. And late last year, the government put out a call for companies to develop drugs that preserve and restore neutrophil counts in radiation syndrome, with secondary emphasis on platelets. So far no such drugs have been approved in the US, but there are candidates.
One obvious option is G-CSF (granulocyte colony-stimulating factor), a cytokine that stimulates the bone marrow to pump out new blood cells. Sold by Amgen of Thousand Oaks, California, to treat neutrophil loss caused by cancer therapy, G-CSF works by preventing the death of the bone-marrow precursor cells destined to become neutrophils, and by boosting their rate of proliferation.
G-CSF is not yet licensed for radiation sickness, but it has been used in 28 cases of accidental radiation exposure and boosted neutrophil counts in 25 of them (although many of the patients died anyway). The animal results also look good. In November, Tom MacVittie of the University of Maryland in Baltimore reported that G-CSF, in combination with supportive care, improved survival rates in irradiated dogs. The US government already has large amounts of G-CSF stored in a strategic national stockpile.
Even so, there are serious doubts over G-CSF's suitability for mass administration in the event of a nuclear terror attack. The drug is expensive, up to $400 per dose, and a patient would typically need daily doses for at least two weeks. It can't be left unrefrigerated for more than 24 hours. Worse still, although it has been given to thousands of cancer patients, side effects are common and can be severe, says Waselenko. Another Amgen cytokine, thrombopoietin (TPO), has shown promise in platelet deficiency, but has been ruled out as a radiation countermeasure because it sometimes causes life-threatening side effects.
Doctor's dilemma
Cytokines' adverse effects present doctors treating radiation syndrome with a dilemma. To save lives you need to treat everyone who might have been exposed, but diagnosing exposures with any real precision takes days, and you don't want to give a drug with potentially serious side effects to people who don't actually need it. One quick-and-dirty sign of serious exposure is nausea and vomiting. The trouble is that almost half of those with dangerous radiation exposure won't vomit, while large numbers of people who are merely traumatised will.
Compounding the problem is the fact that after a detonation, many people will probably be instructed to hunker down in a sheltered spot such as a large building until the fallout has diminished enough to make a dash for it. "These people are going to be several days from even being evaluated," says Waselenko. But you don't have days. G-CSF only works if started within a day or two of irradiation.
So the search is on for better drugs. An ideal radiation countermeasure would be effective, cheap, and easy to make and administer. It would have a long shelf life, minimal side effects if given to someone who turned out not to need it, and would still work even if administered days after exposure. One drug, a steroid called 5-androstenediol or 5-AED, seems to hit most of those targets.
5-AED is cheap, chemically stable and apparently very safe. Developed by Hollis-Eden Pharmaceuticals of La Jolla, California, as an adjunct to chemotherapy, 5-AED was identified as a radioprotectant by Mark Whitnall of the Armed Forces Radiobiology Research Institute (AFRRI) in Bethesda, Maryland, in 1996. It is now being jointly developed as a radiation sickness drug by AFRRI and Hollis-Eden.
Last October, Hollis-Eden announced that in their clinical trial 5-AED significantly increased platelets and neutrophils, without adverse effects, in a group of non-irradiated human volunteers. And in a study led by haematologist Gerard Wagemaker of Erasmus University in Rotterdam, the Netherlands, reported at the annual meeting of the American Society for Hematology in Atlanta, Georgia, in December 2005, 5-AED significantly reduced symptoms in irradiated rhesus monkeys and accelerated the recovery of their neutrophils, platelets, red blood cells and all-important stem cells.
"This steroid exactly mimics the actions of [the platelet-stimulating cytokine] TPO and G-CSF combined - so far, the most effective combination of cytokines for radiation damage to the bone marrow," says Wagemaker.
Although 5-AED is AFRRI's most advanced and, to date, star performer, it's not perfect. Like G-CSF, you need to get it to people quickly: it has yet to be shown effective if used more than a couple of hours after exposure.
Whitnall's team is also looking at other compounds. They have identified some analogues of vitamin E that have mild radioprotective effects in rodents when given prior to irradiation. "At this point we don't really know how they work, though," admits Whitnall. A soybean isoflavone called genistein also appears to provide modest levels of radioprotection, with virtually no side effects. Another very early-stage option is based on stem cells (see "Saved by a cell").
Some other drugs are also racking up good results in mice. One agent, a protein isolated from a parasitic microbe, temporarily switches off cells' programmed suicide apparatus, according to Andre Gudkov, chief scientific officer of the agent's developer, Cleveland Biolabs of Cleveland, Ohio. Fewer self-destructing cells seems to translate into higher survival rates for irradiated mice. Another molecule, developed by Proteome Systems of Sydney, Australia, mimics the ability of two closely paired mitochondrial enzymes, superoxide dismutase and catalase, to scavenge for free radicals, and can also keep irradiated mice alive.
The drive to develop radiation countermeasures could have some everyday pay-offs. For one thing, drugs such as 5-AED might allow us to go back to nuclear power with more confidence. And as Wagemaker points out, ageing populations will become increasingly vulnerable to blood disorders, just as the supply of donors will be dropping. "It is expected that the number of platelet infusions that are needed will at least double in 10 years' time," he warns.
No one knows the real odds of a nuclear attack on a big city. Hopefully, the nightmare will never come true, but if it does, at least there may be a stash of lifesaving drugs waiting in the wings.
Bruce Goldman is a writer based in San Francisco
From issue 2543 of New Scientist magazine, 18 March 2006, page 36
Saved by a cell
Drugs are not the only option for treating people whose bone marrow has been badly damaged by radiation. Cellerant Therapeutics of San Carlos, California, is developing a therapy that is a halfway house between a bone-marrow transplant and a blood transfusion.
After the Chernobyl disaster in 1986, doctors attempted to give bone-marrow transplants to some lethally exposed firefighters. They had little success, in part because it takes weeks for an injection of bone-marrow stem cells to replenish a patient's white blood cells. Cellerant's approach relies on cells called progenitors, which are already part-way along the developmental path leading from stem cell to blood cell and so provide an almost instant supply of replacement blood cells.
Progenitor cells grow easily in the lab and can be frozen until needed. Once thawed and infused into a vein, they start producing neutrophils and other blood cells within a matter of days, and stick around in the body for about six weeks. By then the patient's own damaged bone marrow should be starting to bounce back. And unlike other treatments, progenitor cell therapy ought to work even if it is started several days after exposure.
Radiation biologists like Cellerant's approach. "It makes perfect sense," says Nicholas Dainiak of Yale University. It could also be used in conjunction with drugs such as 5-AED that stimulate the surviving bone marrow.
So will it work in practice? Mice whose bone marrow has been almost completely wiped out survive infections if given a single infusion. In 2007, Cellerant hopes to begin trials in cancer patients who need near-lethal doses of radiation and chemotherapy.
http://www.newscientist.com/article/mg18925431.400.html
Climate: The great hockey stick debate
18 March 2006
NewScientist.com news service
Fred Pearce
It is a persuasive image. Dubbed "the hockey stick" soon after it was first drawn, the graph shows the average temperature over the past 1000 years. For the first 900 or so years there is little variation, like the shaft of an ice-hockey stick. Then, in the 20th century, comes a sharp rise like a hockey stick's blade. The graph seems proof at a glance that we are drastically altering the climate of our planet.
So it is not surprising that the Intergovernmental Panel on Climate Change (IPCC) chose to put the graph in the summary for policymakers in its 2001 report. Some of the scientists must have hoped that the image would become an icon of climate change.
An icon it has certainly become, but not always for the reasons those scientists hoped. For the sceptics who dispute that global warming is real, or say it's nothing to worry about, the graph was like a red rag to a bull. They made it the focus of their attacks, hoping that by demolishing the hockey stick graph they would destroy the credibility of climate scientists and the notion of global warming as a phenomenon caused by human activity.
In the minds of many people they have succeeded. The hockey stick graph is widely regarded as controversial, if not plain wrong. "The hockey stick, the poster-child of the global warming community, turns out to be an artifact of poor mathematics," physicist Richard Muller wrote in Technology Review in 2004. Others have described it as rubbish or even as a downright fraud. So what's all the fuss about? And who should you believe?
The saga began in the late 1990s, when palaeoclimatologist Michael Mann, then at the University of Virginia, and his colleagues embarked on one of the first serious attempts to work out the average global temperature over the past millennium. Direct temperature measurements go back only as far as 1860, so to extend the record back in time they had to use indirect or "proxy" records of temperature, such as the annual rings of trees and isotopic ratios in corals, ice cores and lake sediments.
Such proxy records have been painstakingly assembled by thousands of researchers around the world, but their reliability varies and there are also regional biases. Many records come from temperate parts of Europe and North America, for instance, where scientists are plentiful and trees have clear annual rings; there are very few from the southern hemisphere.
Prior to 1998, attempts to reconstruct past temperatures had been based only on a handful of regional tree-ring records. Mann's team tried to build a more global and reliable picture by including as many proxies from as many different regions as possible. It was pioneering work. The first version of the hockey stick graph, showing average temperatures in the northern hemisphere going back to AD 1400, was published in Nature in 1998.
The following year the team extended the reconstruction back to AD 1000, relying on the few proxy records that go back this far. This 1999 version appeared in the 2001 IPCC report, and is the one to which the term "hockey stick graph" usually refers.
At the time, 1998 was the warmest year on record (now surpassed by 2005, according to NASA), so based partly on Mann's work, the IPCC summary stated that "it is likely that the 1990s was the warmest decade and 1998 the warmest year during the past thousand years". That got headlines. And trouble - not least for the voluble, self-confident Mann. It was the start of a barrage of detailed questions and well-publicised attempted refutations. The hockey stick turned into an implement with which to beat climate scientists.
The debate has spread well beyond the scientific community. Republican senator James Inhofe of Oklahoma, who calls global warming a "hoax", has repeatedly attacked the hockey stick. Last year, Congressman Joe Barton of Texas ordered Mann to provide the House Committee on Energy and Commerce, which Barton chairs, with voluminous details of his working procedures, computer programs and past funding. "There is a concerted effort to undermine the IPCC. There are people who believe that if they bring down Mike Mann, they can bring down the IPCC," says Ben Santer of the Lawrence Livermore Laboratory in California. Santer himself came under attack after writing a chapter in the 1995 IPCC report.
Mann, however, still brims with self-confidence. Now at Penn State University, he treats his critics with something close to contempt. "A lot of scientists would have retreated, but Mike is tenacious," says Gavin Schmidt of the NASA Goddard Institute for Space Studies in New York, his collaborator on the climate science blog RealClimate.
Mann's style does not always help matters. "The goddam guy is a slick talker and super-confident. He won't listen to anyone else," says Wally Broecker of the Lamont-Doherty Earth Observatory at Columbia University in New York. "I don't trust people like that."
“Mann is a slick talker and super-confident. He won't listen to anyone else. I don't trust people like that.”
So the politics is nasty, but what about the science? First, the big picture. The rise in temperatures during the 20th century is generally accepted because it is based on direct measurements. What the hockey stick graph shows is that such a sustained and rapid rise is an anomaly in the context of the past thousand years. This is what you would expect if human activity is to blame for the 20th-century warming, but it is suggestive only. The warming might be caused by natural factors.
Evidence of human involvement comes from many other sources, including climate models. The simulations created by these models can be made to match the temperatures measured over the past 140 years only when the increase in greenhouse gases is included. These graphs also appeared in the 2001 IPCC summary.
The hockey stick has been repeatedly misrepresented as the crucial piece of evidence when it comes to industrialisation and global warming. It is not. Even if the hockey stick were shown to be a doodle that Mann did on a napkin during a night out, the evidence that the world is getting warmer, and that this warming is largely due to human activities, would still be overwhelming.
Fraught with danger
Leaving that aside, did Mann get it right? Does the hockey stick accurately reflect northern hemisphere temperatures over the past 1000 years? There is no doubt that reconstructing past temperatures from proxy data is fraught with danger. Take tree ring records. They sometimes reflect rain or drought rather than temperature. They also get smaller as a tree gets older, so annual or even decadal detail is lost. "You lose roughly 40 per cent of the amplitude of changes," says tree ring specialist Gordon Jacoby at Lamont-Doherty.
To reveal the "signal" behind the noise of short-term and random change, a proxy record for one region must be based on as many tree ring records as possible. It must also correlate with direct measurements of local temperature during the period of overlap - which adds another layer of complication, as in some cases human factors such as pollution might have affected recent tree growth.
So the first question is whether the proxy records Mann chose are reliable indicators of temperature. Some have been questioned. "He has a series from central China that we believe is more a moisture signal than a temperature signal," Jacoby says. "He included it because he had a gap. That was a mistake and it made tree-ring people angry."
Mann accepts that some of the measurements he uses do not directly represent temperature change. His argument is that, for instance, coral records showing rainfall levels in the Pacific are proxies for the El Niño cycle and so for changes in ocean temperatures. Jacoby is not convinced. "I'm not slamming what he did overall. It was a great effort, a great step," he acknowledges. "But he got into hot water by defending it too hard in places where he shouldn't."
Broecker is less accommodating. He says that Mann's hockey stick cannot be right because it does not show the Little Ice Age from roughly 1550 to 1850 or the Medieval Warm Period after 1000, whereas most tree-ring chronologies do show these periods. It is a point seized on by many sceptics, but Mann is unmoved. His point of departure almost a decade ago was that tree ring records alone won't do when it comes to measuring global temperatures, because they are biased towards temperate North America and Europe.
Many other researchers agree. "The Little Ice Age is primarily a European and North Atlantic phenomenon," says Keith Briffa, a tree ring analyst from the University of East Anglia, UK. "And the geographical extent of the Medieval Warm Period is still massively uncertain, because data is sparse."
Indeed, the proxy records suggest that high temperatures in one region tend to be balanced out by low temperatures in another. The tropical Pacific, for instance, appears to have cooled during the Medieval Warm Period and warmed during the Little Ice Age. "The regional temperature changes in our reconstruction are quite large; it's simply that they tend to average out," Mann says.
Most attacks on the hockey stick, however, focus on Mann's statistical methods. The meta-analysis he pioneered, in which different proxy records are merged, involves sorting and aggregating these signals and smoothing the result. Mann then meshed this proxy synthesis with the instrumental record.
Critics complain that by combining smoothed-out proxy data from past centuries with the recent instrumental measurements, which preserve more short-term trends, Mann created a false impression of anomalous recent change. "To be fair, Mann did correct that later on," Jacoby says. This made the blade shorter, but did not change much else. Mann also points out that he was one of the first to include error bars, which show how much variance is lost due to smoothing.
Flaw in methodology
A more serious accusation has come from two non-climate scientists from Canada, who claim to have found a flaw in Mann's statistical methodology. Stephen McIntyre, a mathematician and oil industry consultant, and Ross McKitrick, an economist at the University of Guelph, Ontario, base their criticism on the way Mann used a well-established technique called principal component analysis. This involves dividing "noisy" data into different sets and giving each set an appropriate weighting. McIntyre and McKitrick claim that the way Mann applied this method had the effect of damping down natural variability, straightening the shaft of the hockey stick and accentuating 20th century warming.
There is one sense in which Mann accepts that this is unarguably true. The point of his original work was to compare past and present temperatures, so he analysed temperatures in terms of their divergence from the 20th-century mean. This approach highlights differences from that period and will thus accentuate any hockey stick shape if - but only if, he insists - it is present in the data.
The charge from McIntyre and McKitrick, however, is that Mann's computer program does not merely accentuate this shape, but creates it. To make the point, they did their own analysis based on looking for differences from the mean over the past 1000 years instead of from the 20th-century mean. This produced a graph showing an apparent rise in temperatures in the 15th century as great as the warming occurring now. The shaft of the hockey stick had a big kink in it. When this analysis was published last year in Geophysical Research Letters it was hailed by some as a refutation of Mann's study.
McIntyre and McKitrick say that their work is intended to show only that there are problems with Mann's analysis; they do not claim their graph accurately represents past temperatures. "We have repeatedly made it clear that we offer no alternative reconstruction," McIntyre states on his Climate Audit blog.
The obscure statistical arguments were overshadowed in late 2005 when Mann refused to give Congressman Barton his computer code. Mann regarded the code as private property, but his opponents claimed he feared refutation of his findings. Mann did eventually publish the code, but the damage was done.
In the meantime, three groups had been scrutinising the claims of McIntyre and McKitrick. Hans von Storch of the GKSS Research Centre in Geesthacht, Germany, concluded that McIntyre and McKitrick were right that temperatures should be analysed relative to the 1000-year mean, not the 20th-century mean. But he also found that even when this was done it did not have much effect on the result. Peter Huybers of the Woods Hole Oceanographic Institution in Massachusetts came to much the same conclusion.
The work of Eugene Wahl of Alfred University, New York, and Caspar Ammann of the National Center for Atmospheric Research in Boulder, Colorado, raised serious questions about the methodology of Mann's critics. They found the reason for the kink in the McIntyre and McKitrick graph was nothing to do with their alternative statistical method; instead, it was because they had left out certain proxies, in particular tree-ring studies based on bristlecone pines in the south-west of the US.
"Basically, the McIntyre and McKitrick case boiled down to whether selected North American tree rings should have been included, and not that there was a mathematical flaw in Mann's analysis," Ammann says. The use of the bristlecone pine series has been questioned because of a growth spurt around the end of the 19th century that might reflect higher CO2 levels rather than higher temperatures, and which Mann corrected for.
What counts in science is not a single study, however. It is whether a finding can be replicated by other groups. Here Mann is on a winning streak: upwards of a dozen studies, some using different statistical techniques or different combinations of proxy records (excluding the bristlecone record, for instance), have produced reconstructions more or less similar to the original hockey stick.
More variability
Some reconstructions show much more variability, especially those based only on tree rings, but every reconstruction to date supports the main claim in the IPCC summary: the past decade is likely the warmest for 1000 years (see Graphs). Whatever the flaws in Mann's original work, it seems the broad conclusion is correct.
McIntyre is not impressed. "There is a distinct possibility that researchers have either purposefully or subconsciously selected series with the hockey stick shape," he told one reporter.
The sceptics are unlikely to give up, whatever the conclusions of a panel set up by the US National Academies to assess temperature reconstructions. But for most climate scientists, the controversy is a sideshow. Whatever happened before 1860, the world has been getting warmer since that time, and there is no doubt in their minds that industrialisation is mostly responsible.
What really matters is the future. The IPCC is predicting a rise of between 1.4 and 5.8 °C by 2100. Now take a look at the scale on the hockey stick graph. As Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research in Germany points out: "If humanity takes no action and this century sees a temperature rise of 2 °C, 3 °C or even more, the current discussions over whether the 14th century was a few tenths of a degree warmer or the 17th a few tenths cooler than previously thought will look rather academic."
The subtext of many attacks on the hockey stick is that if the world was warmer 1000 years than it is now, this shows there is nothing unusual going on and we can all stop worrying. Not so, says Briffa. If the world was warmer 1000 years ago, it would suggest the climate system is very sensitive to outside influences, whether past solar cycles or present accumulating greenhouse gases. "Greater past climate variations imply greater future climate change," he says. From this perspective, it would be most worrying if all the hockey sticks really are wrong.
From issue 2543 of New Scientist magazine, 18 March 2006, page 40
http://www.nypost.com/seven/03242006/postopinion/opedcolumnists/61349.htm
Israel and the Ayatollahs
March 24, 2006 -- Some claim they've found the perfect solution to Iran's nuclear ambitions. It's simple: Israel attacks the Islamic Republic to destroy much of its nuclear infrastructure, setting the bomb project back by a decade, time for a more responsible regime to emerge in Tehran.
This would please the Europeans, because it would remove the spotlight from their appeasement policy, which is partly responsible for the crisis. They could shake their heads in a "told you so" gesture at the mullahs, and feel glum about their ability to stand above dirty games played by "immature powers" such as the Islamic Republic and Israel.
Also happy: The Americans (who clearly lack a policy on Iran - indeed, can't even agree on a diagnosis of the problem) and the Arab states, now shaking in their sandals at the prospect of a nuclear-armed Iran.
Russia, too. Hostilty to its neighbor is deep-felt in Iran, which lost territory to Russia in bitter wars with the czars. By the middle of this century, Iran's population will outnumber Russia's. A nuclear-armed Islamic Iran would emerge as an even stronger player.
In short, a great many countries have a direct interest in preventing Iran from going nuclear - yet none is prepared to dirty its hands in the matter. Hence all the talk about Israel taking action.
Yet Israel would not top any list of countries that might be subjected to Iranian nuclear bullying or attack.
Israel has a small air space to defend and is well equipped to destroy missiles launched from Iran. Any nuclear attack by Tehran's terrorist agents in Lebanon and the West Bank, meanwhile, would also kill large numbers in Lebanon and the Palestinian territories.
Yes, the anti-Israeli discourse of Iran's rulers is as virulent as that of Hamas and other Palestinian radical groups. But that discourse is partly prompted by the regime's desire to hide its Shiite identity so that it can claim the leadership of radical Islam, both Shiite and Sunni.
In fact, regardless of who rules in Tehran, Israel and Iran have common strategic interests.
If Israel had never appeared on the map, the energy of pan-Arab nationalism movement, which dominated Arab politics in the post-war era, would have been directed against two other neighbors: Turkey and Iran. To a certain extent, it was anyway. Even today, the Arab League claims that the Turkish province of Iskanderun is "usurped Arab territory" and regards the Iranian province of Khuzestan as "occupied Arab land."
And Arab Sunni Islamism is an even more deadly threat to Iran. It was Arab Sunni Islamism that destroyed the Shiite holy shrines in Iraq in 1802, and returned last month to do so again in Samarra. The same movement is behind the cold-blooded murder of several thousand Iraqi Shiite men, women and children since 2004.
To Arab Sunni Islamists, Iranians are gabrs (Zoroastrians); Shiites, including Arab ones, are rafidis (heretics) who must be "re-converted" or put to death.
Both pan-Arab nationalism and pan-Arab Sunni Islamism are as much mortal foes for Iran as they are for Israel. Neither nation will be safe unless the twin monsters are defeated and the Arab states democratized.
Were Iran to "destroy" Israel, at a huge human cost to itself, it would only be realizing the dream of its own mortal enemies. This is why there is virtually no popular support in Iran for an anti-Israeli policy that goes beyond rhetoric or limited support for Iran's clients in Lebanon, Syria and the Palestinian territories.
Thus, Israel has no reason to assume a responsibility that far stronger powers don't wish to face. In fact, part of Israel's problems stem from the failure of its successive leaders to steer the country clear of other people's quarrels.
In successive wars during the Cold War, Israel destroyed the Soviet-built arsenals of several Arab countries. That helped protect Washington's Arab allies against aggression by pro-Soviet Arab powers - and thus kept the the Soviets from gaining indirect control of the region's vital oil resources. Israel, however, was "rewarded" by not being allowed to translate its military victories into a political settlement that reflected its national interests.
In 1980, Israel knocked out the French-made Iraqi nuclear-weapons center, even though Saddam Hussein was making that bomb to drop on Tehran. The Israeli action helped the major powers avoid catastrophe in a region vital to their interests. Israel's reward? Being described by Jacques Chirac, then mayor of Paris, as "a criminal state."
To be sure, Israel should make it clear that it would retaliate with double force against any attack. But it should also remind those urging it to act that the Islamic Republic's policies, including its quest for nuclear weapons, represent a threat not only to Israel but to many other nations in the Middle East and beyond.
Iranian author Amir Taheri is a member of Benador Associates.
An ode by R.E.M. seems to be spinning in my head.
With the polls for the Israeli elections indicating a victory for Ehud Olmert and Kadima, Muslim rage continuing in Iraq and elsewhere, Hamas and Abu Abbas of the Palestinian Authority continuing political talks, the news regarding Iran’s proclivity in assuring their people that they will be the next evil-axis state to attain nuclear power has been put on the backburner.
The funny thing is that the Iranian Islamists are Shiites who are not Arabs and they wish to be the leaders of both the Sunni and Shiite Pan-Arab nationalist movement.
To Arab Sunni Islamists, Iranians are Zoroastrians. Shiites, including Arab ones, on the other hand, are heretics who must be "re-converted" or put to death.
Of course, that shouldn’t be surprising, with the current trial, in “liberal” Afghanistan, of the Muslim who became a Christian convert facing a possible death sentence. You know, it’s that moral Sharia law.
Well, as Amir Teheri so eloquently put it, everything will be fine as soon as Iran “destroys” Israel. Then Iran’s mortal enemies, i.e. the rest of the Arab world, can focus on destroying Iran. Wow; nuclear proliferation, what a concept!
But why worry about these mundane matters.
In a recent issue of New Scientist, two articles suggest the world really looks like it’s coming to an end.
In the article entitled “grudge match,” the ‘hockey stick’ theory is presented where global warming is presented as a graph whereby the last thousand years appear as the shaft of a hockey stick, with no increase in global warming, while the last few years are the blade of the hockey stick which points up and indicates massive global warming beginning now.
In the second article entitled “Nightmare in Manhattan”, a nightmare scenario is presented whereby a small nuclear device is detonated in New York City.
Oh well, we can still hum R.E. M. songs: ‘First We Take Manhattan…’
See the articles below:
http://www.newscientist.com/channel/health/mg18925431.300.html
Nuclear nightmare in Manhattan
A truck pulls up in front of New York City's Grand Central Station, one of the most densely crowded spots in the world. It is a typical weekday afternoon, with over half a million people in the immediate area, working, shopping or just passing through. A few moments later the driver makes his delivery: a 10-kiloton atomic explosion.
Almost instantly, an electromagnetic pulse knocks out all electronics within a radius of 4 kilometres. The shock wave levels every building within a half-kilometre, killing everyone inside, and severely damages virtually all buildings for a kilometre in every direction. Detonation temperatures of millions of degrees ignite a firestorm that rapidly engulfs the area, generating winds of 600 kilometres an hour.
Within seconds, the blast, heat and direct exposure to radiation have killed several hundred thousand people. Perhaps they are the lucky ones. What follows is, if anything, even worse.
The explosion scoops out a crater 20 metres across and 10 metres deep, sending thousands of tonnes of highly radioactive debris into the air as a cloud of dust. What goes up must come down, and radioactive detritus starts piling up.
Within the first hour, enough fallout settles to fatally irradiate tens of thousands of people in the immediate area. Even 20 kilometres downwind, the majority of people caught in the path of the plume are exposed to life-threatening levels of radioactivity. Anyone less than 30 kilometres downwind will need to get out or find shelter, fast. For 150 kilometres or more downwind of the blast, dangerous amounts of fallout continue to drizzle down.
This nightmare scenario is one the US government is taking seriously. In the past two years alone, it has committed hundreds of millions of dollars to dealing with the aftermath of an act of urban nuclear terrorism, or a 9/11-style attack on a nuclear plant.
Making a bomb is not as difficult as you might imagine. The "gun-type" atomic weapon akin to the one dropped on Hiroshima is essentially a matter of shooting one piece of highly enriched uranium into another. Princeton University physicist Frank von Hippel, in a New York Times interview not long after 9/11, estimated that simply dropping a 45-kilogram lump of weapons-grade uranium onto a second piece of a similar size from a height of about 1.8 metres could produce a blast of 5 to 10 kilotons - that is, the explosive force of 5000 to 10,000 tons of TNT. With enough highly enriched uranium in the world to make hundreds of thousands of such weapons, and frequent reports of nuclear material being stolen from the former Soviet Union, it is far from unthinkable that terrorists could get their hands on enough to make a bomb.
In 2004, a US government-funded working group published an estimate of the number of radiation casualties that would follow a 10-kiloton detonation in a mid-sized city of 2 million, the size of Washington DC (Annals of Internal Medicine, vol 140, p 1037). The numbers make for sobering reading: 13,000 killed immediately; 45,000 facing certain death regardless of treatment; 255,000 at risk of dying without hospital treatment; and a further 140,000 in need of observation. Even a 1-kiloton explosion, from a smaller device or an imperfectly executed detonation, would produce perhaps a third to a half that number of radiation casualties, according to group member Jamie Waselenko of the Sarah Cannon Research Institute in Nashville, Tennessee.
It is the quarter of a million lives that could be saved that are exercising the minds of US policymakers. All of those casualties will be suffering from acute radiation syndrome, otherwise known as radiation sickness. All are potential survivors, but at present there would be little that doctors could do for them.
Most of what is known about radiation sickness comes from animal studies and accidents, and from medical records from Hiroshima and Nagasaki. The syndrome is a collection of symptoms that get progressively worse with increasing exposures. The simplest measure of exposure is a unit called a gray - the number of joules of radiation energy absorbed per kilogram of tissue.
Walking dead
Any exposure above 2 grays or so is deadly serious. People irradiated to this level or higher quickly get sick, then get better again. However, this "latent phase" is only temporary. Some time later, from a few days to a month, they fall ill again, and often die. Not surprisingly, the more radiation you absorb, the more organs are involved, the quicker the immediate symptoms come on and the shorter the latent phase.
The body's most susceptible vital tissue is the bone marrow, specifically the stem cells within it that give rise to new blood cells. These are impaired at doses as low as half a gray and are usually wiped out completely and permanently above 5 grays. When the stem cells die, blood-cell counts - most critically those of neutrophils and platelets - start to drop, eventually plunging to zero after days or weeks. Without neutrophils, the first-responders of the immune system, radiation victims are at high risk of opportunistic infections. Losing platelets is also seriously bad news: without them blood cannot clot, leading to potentially fatal bleeding from even the smallest wound.
Upwards of 5 grays, the gastrointestinal tract is also affected. Radiation kills any rapidly dividing cells, such as the ones lining the intestinal tract. The resulting damage can cause gut bacteria to leak into the bloodstream, where they overwhelm the already compromised immune system and cause septic shock. At exposures above 10 grays, the central nervous system is damaged too, and death is certain, with or without treatment.
The standard treatment for radiation syndrome is "supportive care": blood and platelet transfusions, antimicrobials, fluids, anti-emetics and other "comfort measures". These treatments are better than nothing but are often not enough, and would be extremely difficult to deliver on a mass scale in the aftermath of a nuclear attack. Which means that despite receiving technically survivable doses of radiation, a large proportion of those 255,000 people will die.
The US government is determined to shift the odds in their favour. "What we're aiming to do is to be able to treat every casualty," says Norm Coleman of the National Cancer Institute in Bethesda, Maryland, who has been helping the Department of Health and Human Services plan its response to a nuclear attack.
The government is putting its money where its mouth is. In 2005 it awarded a total of $47 million to several groups of radiation researchers, including $29 million to the newly formed Centers for Medical Countermeasures against Radiation (CMCR). Their mission is to gain a better understanding of the biology of radiation damage, find faster ways of diagnosing radiation exposure levels, and discover better drugs. In July 2004 President Bush signed the Bioshield Act into law, committing $5.6 billion to counter nuclear, biological and chemical threats. And late last year, the government put out a call for companies to develop drugs that preserve and restore neutrophil counts in radiation syndrome, with secondary emphasis on platelets. So far no such drugs have been approved in the US, but there are candidates.
One obvious option is G-CSF (granulocyte colony-stimulating factor), a cytokine that stimulates the bone marrow to pump out new blood cells. Sold by Amgen of Thousand Oaks, California, to treat neutrophil loss caused by cancer therapy, G-CSF works by preventing the death of the bone-marrow precursor cells destined to become neutrophils, and by boosting their rate of proliferation.
G-CSF is not yet licensed for radiation sickness, but it has been used in 28 cases of accidental radiation exposure and boosted neutrophil counts in 25 of them (although many of the patients died anyway). The animal results also look good. In November, Tom MacVittie of the University of Maryland in Baltimore reported that G-CSF, in combination with supportive care, improved survival rates in irradiated dogs. The US government already has large amounts of G-CSF stored in a strategic national stockpile.
Even so, there are serious doubts over G-CSF's suitability for mass administration in the event of a nuclear terror attack. The drug is expensive, up to $400 per dose, and a patient would typically need daily doses for at least two weeks. It can't be left unrefrigerated for more than 24 hours. Worse still, although it has been given to thousands of cancer patients, side effects are common and can be severe, says Waselenko. Another Amgen cytokine, thrombopoietin (TPO), has shown promise in platelet deficiency, but has been ruled out as a radiation countermeasure because it sometimes causes life-threatening side effects.
Doctor's dilemma
Cytokines' adverse effects present doctors treating radiation syndrome with a dilemma. To save lives you need to treat everyone who might have been exposed, but diagnosing exposures with any real precision takes days, and you don't want to give a drug with potentially serious side effects to people who don't actually need it. One quick-and-dirty sign of serious exposure is nausea and vomiting. The trouble is that almost half of those with dangerous radiation exposure won't vomit, while large numbers of people who are merely traumatised will.
Compounding the problem is the fact that after a detonation, many people will probably be instructed to hunker down in a sheltered spot such as a large building until the fallout has diminished enough to make a dash for it. "These people are going to be several days from even being evaluated," says Waselenko. But you don't have days. G-CSF only works if started within a day or two of irradiation.
So the search is on for better drugs. An ideal radiation countermeasure would be effective, cheap, and easy to make and administer. It would have a long shelf life, minimal side effects if given to someone who turned out not to need it, and would still work even if administered days after exposure. One drug, a steroid called 5-androstenediol or 5-AED, seems to hit most of those targets.
5-AED is cheap, chemically stable and apparently very safe. Developed by Hollis-Eden Pharmaceuticals of La Jolla, California, as an adjunct to chemotherapy, 5-AED was identified as a radioprotectant by Mark Whitnall of the Armed Forces Radiobiology Research Institute (AFRRI) in Bethesda, Maryland, in 1996. It is now being jointly developed as a radiation sickness drug by AFRRI and Hollis-Eden.
Last October, Hollis-Eden announced that in their clinical trial 5-AED significantly increased platelets and neutrophils, without adverse effects, in a group of non-irradiated human volunteers. And in a study led by haematologist Gerard Wagemaker of Erasmus University in Rotterdam, the Netherlands, reported at the annual meeting of the American Society for Hematology in Atlanta, Georgia, in December 2005, 5-AED significantly reduced symptoms in irradiated rhesus monkeys and accelerated the recovery of their neutrophils, platelets, red blood cells and all-important stem cells.
"This steroid exactly mimics the actions of [the platelet-stimulating cytokine] TPO and G-CSF combined - so far, the most effective combination of cytokines for radiation damage to the bone marrow," says Wagemaker.
Although 5-AED is AFRRI's most advanced and, to date, star performer, it's not perfect. Like G-CSF, you need to get it to people quickly: it has yet to be shown effective if used more than a couple of hours after exposure.
Whitnall's team is also looking at other compounds. They have identified some analogues of vitamin E that have mild radioprotective effects in rodents when given prior to irradiation. "At this point we don't really know how they work, though," admits Whitnall. A soybean isoflavone called genistein also appears to provide modest levels of radioprotection, with virtually no side effects. Another very early-stage option is based on stem cells (see "Saved by a cell").
Some other drugs are also racking up good results in mice. One agent, a protein isolated from a parasitic microbe, temporarily switches off cells' programmed suicide apparatus, according to Andre Gudkov, chief scientific officer of the agent's developer, Cleveland Biolabs of Cleveland, Ohio. Fewer self-destructing cells seems to translate into higher survival rates for irradiated mice. Another molecule, developed by Proteome Systems of Sydney, Australia, mimics the ability of two closely paired mitochondrial enzymes, superoxide dismutase and catalase, to scavenge for free radicals, and can also keep irradiated mice alive.
The drive to develop radiation countermeasures could have some everyday pay-offs. For one thing, drugs such as 5-AED might allow us to go back to nuclear power with more confidence. And as Wagemaker points out, ageing populations will become increasingly vulnerable to blood disorders, just as the supply of donors will be dropping. "It is expected that the number of platelet infusions that are needed will at least double in 10 years' time," he warns.
No one knows the real odds of a nuclear attack on a big city. Hopefully, the nightmare will never come true, but if it does, at least there may be a stash of lifesaving drugs waiting in the wings.
Bruce Goldman is a writer based in San Francisco
From issue 2543 of New Scientist magazine, 18 March 2006, page 36
Saved by a cell
Drugs are not the only option for treating people whose bone marrow has been badly damaged by radiation. Cellerant Therapeutics of San Carlos, California, is developing a therapy that is a halfway house between a bone-marrow transplant and a blood transfusion.
After the Chernobyl disaster in 1986, doctors attempted to give bone-marrow transplants to some lethally exposed firefighters. They had little success, in part because it takes weeks for an injection of bone-marrow stem cells to replenish a patient's white blood cells. Cellerant's approach relies on cells called progenitors, which are already part-way along the developmental path leading from stem cell to blood cell and so provide an almost instant supply of replacement blood cells.
Progenitor cells grow easily in the lab and can be frozen until needed. Once thawed and infused into a vein, they start producing neutrophils and other blood cells within a matter of days, and stick around in the body for about six weeks. By then the patient's own damaged bone marrow should be starting to bounce back. And unlike other treatments, progenitor cell therapy ought to work even if it is started several days after exposure.
Radiation biologists like Cellerant's approach. "It makes perfect sense," says Nicholas Dainiak of Yale University. It could also be used in conjunction with drugs such as 5-AED that stimulate the surviving bone marrow.
So will it work in practice? Mice whose bone marrow has been almost completely wiped out survive infections if given a single infusion. In 2007, Cellerant hopes to begin trials in cancer patients who need near-lethal doses of radiation and chemotherapy.
http://www.newscientist.com/article/mg18925431.400.html
Climate: The great hockey stick debate
18 March 2006
NewScientist.com news service
Fred Pearce
It is a persuasive image. Dubbed "the hockey stick" soon after it was first drawn, the graph shows the average temperature over the past 1000 years. For the first 900 or so years there is little variation, like the shaft of an ice-hockey stick. Then, in the 20th century, comes a sharp rise like a hockey stick's blade. The graph seems proof at a glance that we are drastically altering the climate of our planet.
So it is not surprising that the Intergovernmental Panel on Climate Change (IPCC) chose to put the graph in the summary for policymakers in its 2001 report. Some of the scientists must have hoped that the image would become an icon of climate change.
An icon it has certainly become, but not always for the reasons those scientists hoped. For the sceptics who dispute that global warming is real, or say it's nothing to worry about, the graph was like a red rag to a bull. They made it the focus of their attacks, hoping that by demolishing the hockey stick graph they would destroy the credibility of climate scientists and the notion of global warming as a phenomenon caused by human activity.
In the minds of many people they have succeeded. The hockey stick graph is widely regarded as controversial, if not plain wrong. "The hockey stick, the poster-child of the global warming community, turns out to be an artifact of poor mathematics," physicist Richard Muller wrote in Technology Review in 2004. Others have described it as rubbish or even as a downright fraud. So what's all the fuss about? And who should you believe?
The saga began in the late 1990s, when palaeoclimatologist Michael Mann, then at the University of Virginia, and his colleagues embarked on one of the first serious attempts to work out the average global temperature over the past millennium. Direct temperature measurements go back only as far as 1860, so to extend the record back in time they had to use indirect or "proxy" records of temperature, such as the annual rings of trees and isotopic ratios in corals, ice cores and lake sediments.
Such proxy records have been painstakingly assembled by thousands of researchers around the world, but their reliability varies and there are also regional biases. Many records come from temperate parts of Europe and North America, for instance, where scientists are plentiful and trees have clear annual rings; there are very few from the southern hemisphere.
Prior to 1998, attempts to reconstruct past temperatures had been based only on a handful of regional tree-ring records. Mann's team tried to build a more global and reliable picture by including as many proxies from as many different regions as possible. It was pioneering work. The first version of the hockey stick graph, showing average temperatures in the northern hemisphere going back to AD 1400, was published in Nature in 1998.
The following year the team extended the reconstruction back to AD 1000, relying on the few proxy records that go back this far. This 1999 version appeared in the 2001 IPCC report, and is the one to which the term "hockey stick graph" usually refers.
At the time, 1998 was the warmest year on record (now surpassed by 2005, according to NASA), so based partly on Mann's work, the IPCC summary stated that "it is likely that the 1990s was the warmest decade and 1998 the warmest year during the past thousand years". That got headlines. And trouble - not least for the voluble, self-confident Mann. It was the start of a barrage of detailed questions and well-publicised attempted refutations. The hockey stick turned into an implement with which to beat climate scientists.
The debate has spread well beyond the scientific community. Republican senator James Inhofe of Oklahoma, who calls global warming a "hoax", has repeatedly attacked the hockey stick. Last year, Congressman Joe Barton of Texas ordered Mann to provide the House Committee on Energy and Commerce, which Barton chairs, with voluminous details of his working procedures, computer programs and past funding. "There is a concerted effort to undermine the IPCC. There are people who believe that if they bring down Mike Mann, they can bring down the IPCC," says Ben Santer of the Lawrence Livermore Laboratory in California. Santer himself came under attack after writing a chapter in the 1995 IPCC report.
Mann, however, still brims with self-confidence. Now at Penn State University, he treats his critics with something close to contempt. "A lot of scientists would have retreated, but Mike is tenacious," says Gavin Schmidt of the NASA Goddard Institute for Space Studies in New York, his collaborator on the climate science blog RealClimate.
Mann's style does not always help matters. "The goddam guy is a slick talker and super-confident. He won't listen to anyone else," says Wally Broecker of the Lamont-Doherty Earth Observatory at Columbia University in New York. "I don't trust people like that."
“Mann is a slick talker and super-confident. He won't listen to anyone else. I don't trust people like that.”
So the politics is nasty, but what about the science? First, the big picture. The rise in temperatures during the 20th century is generally accepted because it is based on direct measurements. What the hockey stick graph shows is that such a sustained and rapid rise is an anomaly in the context of the past thousand years. This is what you would expect if human activity is to blame for the 20th-century warming, but it is suggestive only. The warming might be caused by natural factors.
Evidence of human involvement comes from many other sources, including climate models. The simulations created by these models can be made to match the temperatures measured over the past 140 years only when the increase in greenhouse gases is included. These graphs also appeared in the 2001 IPCC summary.
The hockey stick has been repeatedly misrepresented as the crucial piece of evidence when it comes to industrialisation and global warming. It is not. Even if the hockey stick were shown to be a doodle that Mann did on a napkin during a night out, the evidence that the world is getting warmer, and that this warming is largely due to human activities, would still be overwhelming.
Fraught with danger
Leaving that aside, did Mann get it right? Does the hockey stick accurately reflect northern hemisphere temperatures over the past 1000 years? There is no doubt that reconstructing past temperatures from proxy data is fraught with danger. Take tree ring records. They sometimes reflect rain or drought rather than temperature. They also get smaller as a tree gets older, so annual or even decadal detail is lost. "You lose roughly 40 per cent of the amplitude of changes," says tree ring specialist Gordon Jacoby at Lamont-Doherty.
To reveal the "signal" behind the noise of short-term and random change, a proxy record for one region must be based on as many tree ring records as possible. It must also correlate with direct measurements of local temperature during the period of overlap - which adds another layer of complication, as in some cases human factors such as pollution might have affected recent tree growth.
So the first question is whether the proxy records Mann chose are reliable indicators of temperature. Some have been questioned. "He has a series from central China that we believe is more a moisture signal than a temperature signal," Jacoby says. "He included it because he had a gap. That was a mistake and it made tree-ring people angry."
Mann accepts that some of the measurements he uses do not directly represent temperature change. His argument is that, for instance, coral records showing rainfall levels in the Pacific are proxies for the El Niño cycle and so for changes in ocean temperatures. Jacoby is not convinced. "I'm not slamming what he did overall. It was a great effort, a great step," he acknowledges. "But he got into hot water by defending it too hard in places where he shouldn't."
Broecker is less accommodating. He says that Mann's hockey stick cannot be right because it does not show the Little Ice Age from roughly 1550 to 1850 or the Medieval Warm Period after 1000, whereas most tree-ring chronologies do show these periods. It is a point seized on by many sceptics, but Mann is unmoved. His point of departure almost a decade ago was that tree ring records alone won't do when it comes to measuring global temperatures, because they are biased towards temperate North America and Europe.
Many other researchers agree. "The Little Ice Age is primarily a European and North Atlantic phenomenon," says Keith Briffa, a tree ring analyst from the University of East Anglia, UK. "And the geographical extent of the Medieval Warm Period is still massively uncertain, because data is sparse."
Indeed, the proxy records suggest that high temperatures in one region tend to be balanced out by low temperatures in another. The tropical Pacific, for instance, appears to have cooled during the Medieval Warm Period and warmed during the Little Ice Age. "The regional temperature changes in our reconstruction are quite large; it's simply that they tend to average out," Mann says.
Most attacks on the hockey stick, however, focus on Mann's statistical methods. The meta-analysis he pioneered, in which different proxy records are merged, involves sorting and aggregating these signals and smoothing the result. Mann then meshed this proxy synthesis with the instrumental record.
Critics complain that by combining smoothed-out proxy data from past centuries with the recent instrumental measurements, which preserve more short-term trends, Mann created a false impression of anomalous recent change. "To be fair, Mann did correct that later on," Jacoby says. This made the blade shorter, but did not change much else. Mann also points out that he was one of the first to include error bars, which show how much variance is lost due to smoothing.
Flaw in methodology
A more serious accusation has come from two non-climate scientists from Canada, who claim to have found a flaw in Mann's statistical methodology. Stephen McIntyre, a mathematician and oil industry consultant, and Ross McKitrick, an economist at the University of Guelph, Ontario, base their criticism on the way Mann used a well-established technique called principal component analysis. This involves dividing "noisy" data into different sets and giving each set an appropriate weighting. McIntyre and McKitrick claim that the way Mann applied this method had the effect of damping down natural variability, straightening the shaft of the hockey stick and accentuating 20th century warming.
There is one sense in which Mann accepts that this is unarguably true. The point of his original work was to compare past and present temperatures, so he analysed temperatures in terms of their divergence from the 20th-century mean. This approach highlights differences from that period and will thus accentuate any hockey stick shape if - but only if, he insists - it is present in the data.
The charge from McIntyre and McKitrick, however, is that Mann's computer program does not merely accentuate this shape, but creates it. To make the point, they did their own analysis based on looking for differences from the mean over the past 1000 years instead of from the 20th-century mean. This produced a graph showing an apparent rise in temperatures in the 15th century as great as the warming occurring now. The shaft of the hockey stick had a big kink in it. When this analysis was published last year in Geophysical Research Letters it was hailed by some as a refutation of Mann's study.
McIntyre and McKitrick say that their work is intended to show only that there are problems with Mann's analysis; they do not claim their graph accurately represents past temperatures. "We have repeatedly made it clear that we offer no alternative reconstruction," McIntyre states on his Climate Audit blog.
The obscure statistical arguments were overshadowed in late 2005 when Mann refused to give Congressman Barton his computer code. Mann regarded the code as private property, but his opponents claimed he feared refutation of his findings. Mann did eventually publish the code, but the damage was done.
In the meantime, three groups had been scrutinising the claims of McIntyre and McKitrick. Hans von Storch of the GKSS Research Centre in Geesthacht, Germany, concluded that McIntyre and McKitrick were right that temperatures should be analysed relative to the 1000-year mean, not the 20th-century mean. But he also found that even when this was done it did not have much effect on the result. Peter Huybers of the Woods Hole Oceanographic Institution in Massachusetts came to much the same conclusion.
The work of Eugene Wahl of Alfred University, New York, and Caspar Ammann of the National Center for Atmospheric Research in Boulder, Colorado, raised serious questions about the methodology of Mann's critics. They found the reason for the kink in the McIntyre and McKitrick graph was nothing to do with their alternative statistical method; instead, it was because they had left out certain proxies, in particular tree-ring studies based on bristlecone pines in the south-west of the US.
"Basically, the McIntyre and McKitrick case boiled down to whether selected North American tree rings should have been included, and not that there was a mathematical flaw in Mann's analysis," Ammann says. The use of the bristlecone pine series has been questioned because of a growth spurt around the end of the 19th century that might reflect higher CO2 levels rather than higher temperatures, and which Mann corrected for.
What counts in science is not a single study, however. It is whether a finding can be replicated by other groups. Here Mann is on a winning streak: upwards of a dozen studies, some using different statistical techniques or different combinations of proxy records (excluding the bristlecone record, for instance), have produced reconstructions more or less similar to the original hockey stick.
More variability
Some reconstructions show much more variability, especially those based only on tree rings, but every reconstruction to date supports the main claim in the IPCC summary: the past decade is likely the warmest for 1000 years (see Graphs). Whatever the flaws in Mann's original work, it seems the broad conclusion is correct.
McIntyre is not impressed. "There is a distinct possibility that researchers have either purposefully or subconsciously selected series with the hockey stick shape," he told one reporter.
The sceptics are unlikely to give up, whatever the conclusions of a panel set up by the US National Academies to assess temperature reconstructions. But for most climate scientists, the controversy is a sideshow. Whatever happened before 1860, the world has been getting warmer since that time, and there is no doubt in their minds that industrialisation is mostly responsible.
What really matters is the future. The IPCC is predicting a rise of between 1.4 and 5.8 °C by 2100. Now take a look at the scale on the hockey stick graph. As Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research in Germany points out: "If humanity takes no action and this century sees a temperature rise of 2 °C, 3 °C or even more, the current discussions over whether the 14th century was a few tenths of a degree warmer or the 17th a few tenths cooler than previously thought will look rather academic."
The subtext of many attacks on the hockey stick is that if the world was warmer 1000 years than it is now, this shows there is nothing unusual going on and we can all stop worrying. Not so, says Briffa. If the world was warmer 1000 years ago, it would suggest the climate system is very sensitive to outside influences, whether past solar cycles or present accumulating greenhouse gases. "Greater past climate variations imply greater future climate change," he says. From this perspective, it would be most worrying if all the hockey sticks really are wrong.
From issue 2543 of New Scientist magazine, 18 March 2006, page 40
http://www.nypost.com/seven/03242006/postopinion/opedcolumnists/61349.htm
Israel and the Ayatollahs
March 24, 2006 -- Some claim they've found the perfect solution to Iran's nuclear ambitions. It's simple: Israel attacks the Islamic Republic to destroy much of its nuclear infrastructure, setting the bomb project back by a decade, time for a more responsible regime to emerge in Tehran.
This would please the Europeans, because it would remove the spotlight from their appeasement policy, which is partly responsible for the crisis. They could shake their heads in a "told you so" gesture at the mullahs, and feel glum about their ability to stand above dirty games played by "immature powers" such as the Islamic Republic and Israel.
Also happy: The Americans (who clearly lack a policy on Iran - indeed, can't even agree on a diagnosis of the problem) and the Arab states, now shaking in their sandals at the prospect of a nuclear-armed Iran.
Russia, too. Hostilty to its neighbor is deep-felt in Iran, which lost territory to Russia in bitter wars with the czars. By the middle of this century, Iran's population will outnumber Russia's. A nuclear-armed Islamic Iran would emerge as an even stronger player.
In short, a great many countries have a direct interest in preventing Iran from going nuclear - yet none is prepared to dirty its hands in the matter. Hence all the talk about Israel taking action.
Yet Israel would not top any list of countries that might be subjected to Iranian nuclear bullying or attack.
Israel has a small air space to defend and is well equipped to destroy missiles launched from Iran. Any nuclear attack by Tehran's terrorist agents in Lebanon and the West Bank, meanwhile, would also kill large numbers in Lebanon and the Palestinian territories.
Yes, the anti-Israeli discourse of Iran's rulers is as virulent as that of Hamas and other Palestinian radical groups. But that discourse is partly prompted by the regime's desire to hide its Shiite identity so that it can claim the leadership of radical Islam, both Shiite and Sunni.
In fact, regardless of who rules in Tehran, Israel and Iran have common strategic interests.
If Israel had never appeared on the map, the energy of pan-Arab nationalism movement, which dominated Arab politics in the post-war era, would have been directed against two other neighbors: Turkey and Iran. To a certain extent, it was anyway. Even today, the Arab League claims that the Turkish province of Iskanderun is "usurped Arab territory" and regards the Iranian province of Khuzestan as "occupied Arab land."
And Arab Sunni Islamism is an even more deadly threat to Iran. It was Arab Sunni Islamism that destroyed the Shiite holy shrines in Iraq in 1802, and returned last month to do so again in Samarra. The same movement is behind the cold-blooded murder of several thousand Iraqi Shiite men, women and children since 2004.
To Arab Sunni Islamists, Iranians are gabrs (Zoroastrians); Shiites, including Arab ones, are rafidis (heretics) who must be "re-converted" or put to death.
Both pan-Arab nationalism and pan-Arab Sunni Islamism are as much mortal foes for Iran as they are for Israel. Neither nation will be safe unless the twin monsters are defeated and the Arab states democratized.
Were Iran to "destroy" Israel, at a huge human cost to itself, it would only be realizing the dream of its own mortal enemies. This is why there is virtually no popular support in Iran for an anti-Israeli policy that goes beyond rhetoric or limited support for Iran's clients in Lebanon, Syria and the Palestinian territories.
Thus, Israel has no reason to assume a responsibility that far stronger powers don't wish to face. In fact, part of Israel's problems stem from the failure of its successive leaders to steer the country clear of other people's quarrels.
In successive wars during the Cold War, Israel destroyed the Soviet-built arsenals of several Arab countries. That helped protect Washington's Arab allies against aggression by pro-Soviet Arab powers - and thus kept the the Soviets from gaining indirect control of the region's vital oil resources. Israel, however, was "rewarded" by not being allowed to translate its military victories into a political settlement that reflected its national interests.
In 1980, Israel knocked out the French-made Iraqi nuclear-weapons center, even though Saddam Hussein was making that bomb to drop on Tehran. The Israeli action helped the major powers avoid catastrophe in a region vital to their interests. Israel's reward? Being described by Jacques Chirac, then mayor of Paris, as "a criminal state."
To be sure, Israel should make it clear that it would retaliate with double force against any attack. But it should also remind those urging it to act that the Islamic Republic's policies, including its quest for nuclear weapons, represent a threat not only to Israel but to many other nations in the Middle East and beyond.
Iranian author Amir Taheri is a member of Benador Associates.
posted by judah h | 3:06 PM
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